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# Copyright 2018-2021 Gentoo Authors
# Distributed under the terms of the GNU General Public License v2
from concurrent.futures import Future, ThreadPoolExecutor
import contextlib
try:
import threading
except ImportError:
import dummy_threading as threading
import weakref
import time
import portage
from portage.tests import TestCase
from portage.util._eventloop.global_event_loop import global_event_loop
from portage.util.backoff import RandomExponentialBackoff
from portage.util.futures import asyncio
from portage.util.futures.retry import retry
from portage.util.futures.executor.fork import ForkExecutor
class SucceedLaterException(Exception):
pass
class SucceedLater:
"""
A callable object that succeeds some duration of time has passed.
"""
def __init__(self, duration):
self._succeed_time = time.monotonic() + duration
async def __call__(self):
remaining = self._succeed_time - time.monotonic()
if remaining > 0:
await asyncio.sleep(remaining)
return "success"
class SucceedNeverException(Exception):
pass
class SucceedNever:
"""
A callable object that never succeeds.
"""
async def __call__(self):
raise SucceedNeverException("expected failure")
class HangForever:
"""
A callable object that sleeps forever.
"""
async def __call__(self):
while True:
await asyncio.sleep(9)
class RetryTestCase(TestCase):
@contextlib.contextmanager
def _wrap_coroutine_func(self, coroutine_func):
"""
Derived classes may override this method in order to implement
alternative forms of execution.
"""
yield coroutine_func
def testSucceedLater(self):
loop = global_event_loop()
with self._wrap_coroutine_func(SucceedLater(1)) as func_coroutine:
decorator = retry(
try_max=9999,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
result = loop.run_until_complete(decorated_func())
self.assertEqual(result, "success")
def testSucceedNever(self):
loop = global_event_loop()
with self._wrap_coroutine_func(SucceedNever()) as func_coroutine:
decorator = retry(
try_max=4,
try_timeout=None,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(
isinstance(done.pop().exception().__cause__, SucceedNeverException)
)
def testSucceedNeverReraise(self):
loop = global_event_loop()
with self._wrap_coroutine_func(SucceedNever()) as func_coroutine:
decorator = retry(
reraise=True,
try_max=4,
try_timeout=None,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(isinstance(done.pop().exception(), SucceedNeverException))
def testHangForever(self):
loop = global_event_loop()
with self._wrap_coroutine_func(HangForever()) as func_coroutine:
decorator = retry(
try_max=2,
try_timeout=0.1,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(
isinstance(done.pop().exception().__cause__, asyncio.TimeoutError)
)
def testHangForeverReraise(self):
loop = global_event_loop()
with self._wrap_coroutine_func(HangForever()) as func_coroutine:
decorator = retry(
reraise=True,
try_max=2,
try_timeout=0.1,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(isinstance(done.pop().exception(), asyncio.TimeoutError))
def testCancelRetry(self):
loop = global_event_loop()
with self._wrap_coroutine_func(SucceedNever()) as func_coroutine:
decorator = retry(
try_timeout=0.1,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
future = decorated_func()
loop.call_later(0.3, future.cancel)
done, pending = loop.run_until_complete(asyncio.wait([future], loop=loop))
self.assertEqual(len(done), 1)
self.assertTrue(done.pop().cancelled())
def testOverallTimeoutWithException(self):
loop = global_event_loop()
with self._wrap_coroutine_func(SucceedNever()) as func_coroutine:
decorator = retry(
try_timeout=0.1,
overall_timeout=0.3,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(
isinstance(done.pop().exception().__cause__, SucceedNeverException)
)
def testOverallTimeoutWithTimeoutError(self):
loop = global_event_loop()
# results in TimeoutError because it hangs forever
with self._wrap_coroutine_func(HangForever()) as func_coroutine:
decorator = retry(
try_timeout=0.1,
overall_timeout=0.3,
delay_func=RandomExponentialBackoff(multiplier=0.1, base=2),
)
decorated_func = decorator(func_coroutine, loop=loop)
done, pending = loop.run_until_complete(
asyncio.wait([decorated_func()], loop=loop)
)
self.assertEqual(len(done), 1)
self.assertTrue(
isinstance(done.pop().exception().__cause__, asyncio.TimeoutError)
)
class RetryForkExecutorTestCase(RetryTestCase):
"""
Wrap each coroutine function with AbstractEventLoop.run_in_executor,
in order to test the event loop's default executor. The executor
may use either a thread or a subprocess, and either case is
automatically detected and handled.
"""
def __init__(self, *pargs, **kwargs):
super(RetryForkExecutorTestCase, self).__init__(*pargs, **kwargs)
self._executor = None
def _setUpExecutor(self):
self._executor = ForkExecutor()
def _tearDownExecutor(self):
if self._executor is not None:
self._executor.shutdown(wait=True)
self._executor = None
def setUp(self):
self._setUpExecutor()
def tearDown(self):
self._tearDownExecutor()
@contextlib.contextmanager
def _wrap_coroutine_func(self, coroutine_func):
parent_loop = global_event_loop()
parent_pid = portage.getpid()
pending = weakref.WeakValueDictionary()
# Since ThreadPoolExecutor does not propagate cancellation of a
# parent_future to the underlying coroutine, use kill_switch to
# propagate task cancellation to wrapper, so that HangForever's
# thread returns when retry eventually cancels parent_future.
def wrapper(kill_switch):
if portage.getpid() == parent_pid:
# thread in main process
def done_callback(result):
result.cancelled() or result.exception() or result.result()
kill_switch.set()
def start_coroutine(future):
result = asyncio.ensure_future(coroutine_func(), loop=parent_loop)
pending[id(result)] = result
result.add_done_callback(done_callback)
future.set_result(result)
future = Future()
parent_loop.call_soon_threadsafe(start_coroutine, future)
kill_switch.wait()
if not future.done():
future.cancel()
raise asyncio.CancelledError
elif not future.result().done():
future.result().cancel()
raise asyncio.CancelledError
else:
return future.result().result()
# child process
loop = global_event_loop()
try:
return loop.run_until_complete(coroutine_func())
finally:
loop.close()
def execute_wrapper():
kill_switch = threading.Event()
parent_future = asyncio.ensure_future(
parent_loop.run_in_executor(self._executor, wrapper, kill_switch),
loop=parent_loop,
)
def kill_callback(parent_future):
if not kill_switch.is_set():
kill_switch.set()
parent_future.add_done_callback(kill_callback)
return parent_future
try:
yield execute_wrapper
finally:
while True:
try:
_, future = pending.popitem()
except KeyError:
break
try:
parent_loop.run_until_complete(future)
except (Exception, asyncio.CancelledError):
pass
future.cancelled() or future.exception() or future.result()
class RetryThreadExecutorTestCase(RetryForkExecutorTestCase):
def _setUpExecutor(self):
self._executor = ThreadPoolExecutor(max_workers=1)
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